class_docstr: A DDPG Agent.
code: def _initialize(self):
      common.soft_variables_update(
          self._critic_network.variables,
          self._target_critic_network.variables,
          tau=1.0,
      )
      common.soft_variables_update(
          self._actor_network.variables,
          self._target_actor_network.variables,
          tau=1.0,
      )
  
imports: from __future__ import absolute_import
  from __future__ import division
  from __future__ import print_function
  import collections
  from typing import Optional, Text
  import gin
  import tensorflow
  from tf_agents.agents import data_converter
  from tf_agents.agents import tf_agent
  from tf_agents.networks import network
  from tf_agents.policies import actor_policy
  from tf_agents.policies import ou_noise_policy
  from tf_agents.trajectories import time_step
  from tf_agents.typing import types
  from tf_agents.utils import common
  from tf_agents.utils import eager_utils
  from tf_agents.utils import nest_utils
label_desc: Use image node_id 2 for calling the DdpgAgent obj's underlying member method code with example usage: obj._initialize() without return types